We recommend that OEMs, cloud service providers, system manufacturers, software vendors and end users stop deployment of current versions, as they may introduce higher than expected reboots and other unpredictable system behavior.

This is a blow to industry efforts to fix this vulnerability, a process involving BIOS updates (to install the microcode) as well as operating system patches.

Intel says it has an “early version of the updated solution”. Given the length of time it takes for PC manufacturers to package and distribute BIOS updates for the many thousands of models affected, it looks like the moment at which the majority of active systems will be patched is now far in the future.

Vendors have not yet completed the rollout of the initial patch, which they are now being asked to withdraw.

The detailed microcode guidance is here. Intel also has a workaround which gives some protection while also preserving system stability:

For those concerned about system stability while we finalize the updated solutions, we are also working with our OEM partners on the option to utilize a previous version of microcode that does not display these issues, but removes the Variant 2 (Spectre) mitigations. This would be delivered via a BIOS update, and would not impact mitigations for Variant 1 (Spectre) and Variant 3 (Meltdown).

I am not sure who out there is not concerned about system stability? That said, public cloud vendors would rather almost anything than the possibility of code running in one VM getting unauthorised access to the host or to other VMs.

Right now it feels as if most of the world’s computing devices, from server to smartphone, are simply insecure. Though it should be noted that the bad guys have to get their code to run: trivial if you just need to run up a VM on a public cloud, more challenging if it is a server behind a firewall.